Heucherella plant named ‘Onyx’

ABSTRACT

A new and distinct x  Heucherella  plant substantially as shown and described, characterized by leaves dark red brown in spring to almost black for the rest of the year, glossy, palmately cut leaves that are sometimes puckered, a medium mounding habit with an excellent crown count, and excellent vigor.

Botanical denomination: x Heucherella hybrid. Variety designation: ‘Onyx’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of x Heucherella and given the cultivar name of ‘Onyx’. x Heucherella is in the family Saxifragaceae. x Heucherella ‘Onyx’ originated from a controlled cross between Heuchera ‘B110-5’ (a proprietary, unpatented, unreleased Heuchera), as the seed parent, and Tiarella ‘42-2’ (a proprietary, unpatented, unreleased Tiarella), as the pollen parent.

Compared to the seed parent Heuchera ‘B110-5’, the new cultivar has cut leaves rather than shallowly lobed leaves.

Compared to the pollen parent Tiarella ‘42-2’, the new cultivar has glossy black leaves rather than matte green.

Compared to x Heucherella ‘Burnished Bronze’, U.S. Plant Pat. No. 12,159, the new cultivar has thicker leaves that are much darker and cupped on margins, it is more vigorous, and the habit is larger and more mounding.

This new x Heucherella is uniquely characterized by:

-   -   1. leaves dark red brown in spring to almost black for the rest         of the year,     -   2. glossy, palmately cut leaves that are sometimes puckered,     -   3. a medium mounding habit with an excellent crown count, and     -   4. excellent vigor.

This new cultivar has been reproduced only by asexual propagation (cuttings and tissue culture using growing points at the crown). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by division and tissue culture using standard micropropagation techniques with terminal and lateral shoots, as done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an eight-month-old plant in the garden in part shade in late April in Canby, Oreg.

FIG. 2 shows the same plant in a garden group in mid-May in Canby, Oreg.

DETAILED PLANT DESCRIPTION

The following is a detailed description of the new x Heucherella cultivar based on observations of 8-month-old specimens grown in the trial field grown in part shade late September in Canby, Oreg. Canby is Zone 8 on the USDA Hardiness map. Temperatures range from a high of 95° F. in August to an average of 32° F. in January. Normal rainfall in Canby is 42.8 inches per year. The color descriptions are all based on The Royal Horticultural Society Colour Chart, 5^(th) edition, 2007.

-   Plant:     -   -   Type.—Herbaceous perennial.         -   Form.—Basal rosette.         -   Hardiness.—USDA Zone 4 to 9.         -   Size.—15 cm tall from top of the foliage to the ground and             40 cm wide before trailing down.         -   Habit.—Mounding with 15 crowns.         -   Vigor.—Excellent.         -   Roots.—Fibrous, freely branching, fine and White 155A in             color. -   Leaf:     -   -   Type.—Simple.         -   Arrangement.—Rosette.         -   Shape.—Broadly ovate.         -   Blade size.—Grow to 13.5 cm long and 11 cm wide.         -   Lobing/division.—3 to 5 main palmate divisions cut ¾ of the             way to the main vein each with secondary lobes cut to ½ to             the secondary veins.         -   Venation.—Palmate.         -   Margins.—Broadly crenate and slightly undulate.         -   Apex.—Obtuse to mucronulate.         -   Base.—Cordate, overlapping.         -   Surface texture.—Glandular hairs on both surfaces, often             puckered.         -   Leaf rugosity.—Weak to medium.         -   Glossiness.—Strong.         -   Petiole description.—Grows to 13 cm long and 2.5 mm wide,             with glandular hairs and Greyed Purple 187A.         -   Leaf color.—Spring topside Greyed Purple N186C with veins             187B, bottom side Greyed Purple N186C including veins;             summer through winter topside Greyed Purple N186A with veins             N199A, bottom side Purple N77 including veins. -   Inflorescence:     -   -   Size.—Usually 12 cm long and 3.5 mm wide.         -   Type.—Upright to semi-upright raceme.         -   Number of flowers per raceme.—About 65.         -   Density of flowers in raceme.—Medium.         -   Number of racemes.—About 8.         -   Peduncle.—Grows to 37 cm long, 4 mm wide at base, 1 to 2             petiolate floral leaves (blades grow to 6 cm long and 5.5 cm             wide, ovate, 3 main divisions and 1 to 3 lobed, tip             mucronulate, margin crenate, base cordate, glandular hairs             on bottom side, topside glabrous other than margins, Greyed             Purple N186C, bottom side Greyed Purple N186C).         -   Pedicel.—Grows to 3 mm long, with glandular hairs, Greyed             Orange 177A.         -   Bloom period.—May through June in Canby, Oreg. -   Flower bud:     -   -   Size.—4 mm long and 2.5 mm wide.         -   Description.—Glandular puberulent, ovoid, down to             side-facing.         -   Color.—Greyed Yellow 161D. -   Flower:     -   -   Type.—Imperfect.         -   Shape.—Campanulate.         -   Attitude.—Side-facing.         -   Size.—6 mm deep and 7 mm wide.         -   Petal description.—5 in number, stellate, spatulate, 4 mm             long and 1.5 mm wide, tip acuminate, base attenuate, margin             entire, glabrous and Red Purple 65C on both sides.         -   Calyx description.—6 mm deep and 7 mm wide, campanulate,             with 5 lobes, divided ½ way to the base, lobes 3 mm long and             2 mm wide, oblong, glandular hairs on both sides, tip             obtuse, margin entire, White NN155B on both sides with tips             Greyed White 156A on inside.         -   Stamen description.—10, 3 mm long, filament 3 mm long and             White NN155B, anthers Greyed Orange 177A, no pollen.         -   Pistil description.—1 in number, grows to 5 mm long and 2.5             mm wide, ovaries grow to 1.5 mm long and 2.5 wide, White             NN155B, beaked style 3 mm long, Red Purple 69C.         -   Fragrance.—None.         -   Lastingness.—Each raceme blooms for about 2 weeks on the             plant. -   Fruit and seed: None. -   Disease and pest tolerance: The new cultivar is typical to the     genus. No known resistances to pests or diseases. No problems have     been found in Canby, Oreg. 

I claim:
 1. A new and distinct x Heucherella plant as herein illustrated and described. 